CN114280377B - Detection method for air conditioner precharge circuit detection circuit and air conditioner - Google Patents

Detection method for air conditioner precharge circuit detection circuit and air conditioner Download PDF

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CN114280377B
CN114280377B CN202111510362.1A CN202111510362A CN114280377B CN 114280377 B CN114280377 B CN 114280377B CN 202111510362 A CN202111510362 A CN 202111510362A CN 114280377 B CN114280377 B CN 114280377B
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circuit
voltage
relay
bus
air conditioner
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CN114280377A (en
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褚艳伟
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Abstract

The invention provides a detection method for an air conditioner precharge circuit detection circuit and an air conditioner, wherein the detection circuit comprises the following steps: the detected part: a bus capacitor circuit; the detection part: the relay circuit, the voltage circuit and the main controller; the input end of the main controller is connected with the relay circuit, the relay circuit is connected with the bus capacitor circuit, the bus capacitor circuit is connected with the voltage circuit, and the output end of the voltage circuit is connected with the main controller. The invention can detect whether the capacitance value of the bus capacitor is reduced or fails before the air conditioner operates, can timely find the aging failure of the capacitor, and can send out a failure signal when the capacitance value of the bus capacitor is reduced and fails, so that the air conditioner is started under the condition of failure, the personal safety is endangered, and the reliability and the safety of equipment operation are improved.

Description

Detection method for air conditioner precharge circuit detection circuit and air conditioner
Technical Field
The invention relates to the field of air conditioners, in particular to a detection method for an air conditioner precharge circuit detection circuit and an air conditioner.
Background
The bus capacitor is an important component of the air conditioner controller and plays roles of filtering and energy storage in a circuit. The bus voltage of the air conditioner controller cannot be directly applied to the bus capacitor, and the capacitor needs to be charged by controlling the bus voltage through a pre-charging circuit in the air conditioner system.
However, capacitor aging occurs when the capacitor is over-heated, over-voltage, over-current or overloaded during operation, and an important manifestation of capacitor aging is a decrease in capacitance. The capacitance value is reduced, so that the filtering and energy storage effects are reduced, the normal operation of the subsequent inversion and power supply parts is influenced, and the equipment and personal safety are greatly threatened.
Disclosure of Invention
In order to overcome the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a detection method for an air conditioner precharge circuit detection circuit and an air conditioner, so as to solve the above-mentioned problems.
The technical scheme adopted for solving the technical problems is as follows:
an air conditioner precharge circuit detection circuit, wherein the detection circuit comprises:
the detected part: a bus capacitor circuit;
the detection part: the relay circuit, the voltage circuit and the main controller;
the input end of the main controller is connected with the relay circuit, the relay circuit is connected with the bus capacitor circuit, the bus capacitor circuit is connected with the voltage circuit, and the output end of the voltage circuit is connected with the main controller.
As a further improvement of the invention: the relay circuit comprises a relay driving circuit, a relay and a relay voltage; one end of the relay driving circuit is connected with the main controller, the other end of the relay driving circuit is connected with the relay, and the other end of the relay is respectively connected with the relay voltage and the bus capacitor circuit.
As a further improvement of the invention: the relay driving circuit comprises a second resistor, a third resistor and a triode, wherein the second resistor is respectively connected with the third resistor and the triode, the other end of the third resistor is connected with the triode, the triode is connected with the relay, and the second resistor is connected with the main controller.
As a further improvement of the invention: the voltage circuit comprises a voltage comparator, a voltage follower, a second bus charging voltage and a third bus charging voltage; one end of the voltage comparator is connected with the main controller, and the other end of the voltage comparator is respectively connected with the voltage follower, the second bus charging voltage and the third bus charging voltage; and the other end of the voltage follower is respectively connected with the second bus charging voltage and the bus capacitor circuit.
As a further improvement of the invention: the bus capacitor circuit comprises a bus capacitor, a first bus charging voltage and a charging resistor; one end of the bus capacitor is connected with the relay circuit, the other end of the bus capacitor is connected with the first bus charging voltage, the other end of the first bus charging voltage is connected with the charging resistor, and the charging resistor is connected with the voltage circuit.
As a further improvement of the invention: the main controller is a main control chip MCU.
An air conditioner pre-charge loop detection method, wherein the air conditioner pre-charge loop detection circuit comprises a charging resistor voltage V R1 The method comprises the following steps:
the control chip sends out a high-level signal H1 and starts timing;
the relay receives a high-level signal H1 to drive the relay to be closed, and the charging voltage of the first bus starts to charge the capacitor through the charging resistor;
judging the voltage V of the charging resistor R1 Whether less than the steady state voltage division across the charging resistor R1;
if yes, the control chip receives the low level signal, stops timing and calculates the time difference, and marks as DeltaT 3 ,△T 3 The method comprises the steps that the difference value between a timing value after a control chip receives a low-level signal and a timing value after a previous control chip receives the low-level signal is obtained;
if not, the capacitor continues to charge.
As a further improvement of the invention: after stopping timing and calculating the time difference, the method also comprises a capacitor aging judging method, which comprises the following steps:
determining a time difference DeltaT 3 Whether the time difference set value delta T is larger than the time difference set value delta T;
if yes, judging that the capacitor is aged, and sending an alarm signal by the main controller;
if not, judging that the capacitor is not aged, and the circuit works normally.
An air conditioner comprising an air conditioner precharge circuit detection circuit as claimed in any preceding claim.
An air conditioner comprising a detection method for an air conditioner precharge circuit detection circuit as claimed in any one of the preceding claims.
Compared with the prior art, the invention has the beneficial effects that:
whether the capacitance value of the bus capacitor is reduced or fails can be detected before the air conditioner operates, the aging failure of the capacitor can be found in time, and a failure signal can be sent out when the capacitance value of the bus capacitor is reduced and fails, so that the air conditioner is started under the condition of failure, the personal safety is endangered, and meanwhile, the reliability and the safety of equipment operation are improved.
Drawings
Fig. 1 is a schematic circuit structure of the present invention.
FIG. 2 is a flow chart of the detection method of the present invention.
FIG. 3 is a waveform diagram of the bus capacitor voltage according to the present invention.
Fig. 4 is a waveform diagram of the charging resistor R1 according to the present invention.
FIG. 5 is a chart showing the comparison of the charging time and the capacitance of the bus capacitor according to the present invention.
Description of the embodiments
The invention will now be further described with reference to the accompanying drawings and examples:
the invention provides an air conditioner pre-charge loop detection circuit as shown in fig. 1, wherein the detection circuit comprises:
the detected part: a bus capacitor circuit;
the detection part: the relay circuit, the voltage circuit and the main controller;
the input end of the main controller is connected with the relay circuit, the relay circuit is connected with the bus capacitor circuit, the bus capacitor circuit is connected with the voltage circuit, and the output end of the voltage circuit is connected with the main controller.
The invention provides an air conditioner controller precharge circuit detection circuit, which aims at the problem that a precharge circuit in the existing air conditioner system cannot timely respond to the aging fault of a bus capacitor. The safety of users and equipment is guaranteed to the greatest extent, and the safety is improved.
The invention is described in further detail below, as shown in fig. 1: the relay circuit comprises a relay driving circuit, a relay and a relay voltage; one end of the relay driving circuit is connected with the main controller, the other end of the relay driving circuit is connected with the relay, and the other end of the relay is respectively connected with the relay voltage and the bus capacitor circuit.
A further description of the relay circuit is shown in fig. 1: the relay driving circuit comprises a second resistor, a third resistor and a triode, wherein the second resistor is respectively connected with the third resistor and the triode, the other end of the third resistor is connected with the triode, the triode is connected with the relay, and the second resistor is connected with the main controller.
The voltage circuit is further described: the voltage circuit comprises a voltage comparator, a voltage follower, a second bus charging voltage and a third bus charging voltage; one end of the voltage comparator is connected with the main controller, and the other end of the voltage comparator is respectively connected with the voltage follower, the second bus charging voltage and the third bus charging voltage; and the other end of the voltage follower is respectively connected with the second bus charging voltage and the bus capacitor circuit.
A further description of the bus capacitor circuit is provided with reference to fig. 1: the bus capacitor circuit comprises a bus capacitor, a first bus charging voltage and a charging resistor; one end of the bus capacitor is connected with the relay circuit, the other end of the bus capacitor is connected with the first bus charging voltage, the other end of the first bus charging voltage is connected with the charging resistor, and the charging resistor is connected with the voltage circuit.
In the invention, the optimal choice of the main controller is the main control chip MCU. The MCU of the main control chip has simple algorithm, and only needs to receive fault signals, thereby greatly improving the operation reliability and safety of the equipment.
The invention also provides a detection method of the air conditioner pre-charge loop shown in the figure 2, wherein the detection method is used in the air conditioner pre-charge loop detection circuit according to any one of the above, and comprises a charging resistor voltage V R1 The method comprises the following steps:
the control chip sends out a high-level signal H1 and starts timing;
the relay receives a high-level signal H1 to drive the relay to be closed, and the charging voltage of the first bus starts to charge the capacitor through the charging resistor;
judging the voltage V of the charging resistor R1 Whether less than the steady state voltage division across the charging resistor R1;
if yes, the control chip receives the low level signal, stops timing and calculates the time difference, and marks as DeltaT 1 ,△T 1 The method comprises the steps that the difference value between a timing value after a control chip receives a low-level signal and a time value after the control chip receives the low-level signal in the previous time is obtained;
if not, the capacitor continues to charge.
The detection method of the invention is further described, as shown in fig. 2: after stopping timing and calculating the time difference, the method also comprises a capacitor aging judging method, which comprises the following steps:
determining a time difference DeltaT 1 Whether the time difference set value delta T is larger than the time difference set value delta T;
if yes, judging that the capacitor is aged, and sending an alarm signal by the main controller;
if not, judging that the capacitor is not aged, and the circuit works normally.
In one embodiment of the invention, an air conditioner is included, wherein an air conditioner precharge circuit detection circuit as described in any of the above is included.
In another embodiment of the present invention, an air conditioner is provided, wherein the method for detecting a precharge circuit of an air conditioner according to any one of the above description is included.
The present invention is described in detail below:
the working principle of the invention is as follows:
when the bus capacitor has a capacity reduction fault due to aging, the air conditioner controller precharge circuit detection circuit can detect whether the capacity of the bus capacitor is reduced or not and send a fault signal to the MCU, so that the MCU can take protective measures to protect personal safety and equipment safety.
According to the busbar capacitance voltage waveform diagram shown in fig. 3, the horizontal axis represents time in seconds, and the vertical axis represents voltage in volts. VCC1 is bus charging voltage, T1 is the time to reach charging power supply voltage.
According to the charge resistor R1 waveform shown in fig. 4, the horizontal axis represents time in seconds, and the vertical axis represents voltage in volts. VCC1 is a bus charging voltage, and VCC3 is a steady-state voltage division across the charging resistor R1. T2 is the time to reach steady state.
Fig. 1 is a working flow chart of the invention, as shown in fig. 1, when the detection circuit starts working, the control chip sends a high level signal H1 and starts timing, the relay driving circuit receives the signal and starts timing, the relay K1 is driven to be closed, the circuit forms a channel, the bus voltage VCC1 charges the capacitor through the charging resistor R1, the capacitor voltage is continuously increased in the charging process, the voltage of the charging resistor R1 is continuously reduced, when the voltage across the charging resistor R1 is smaller than the set value VCC3, the L1 is changed from high level to low level, and the control chip stops timing and calculates the charging time T3 after receiving the signal. T3 and the initial charge time T3 1 Comparing to obtain a difference DeltaT 3 When the difference is DeltaT 3 When the capacitance value of the capacitor is larger than the time difference set value delta T, the capacitance value of the capacitor is judged to be excessively reduced, and the capacitor is seriously aged.
DeltaT represents the first charge time T3 of the capacitor 1 Charging time T3 corresponding to capacitance value CM when capacitor is aged and failed N N is the number of charging times, T3 N The time required for the nth charge is as shown in fig. 5.
Specific embodiments of the invention:
with the increasing global warming, the power electronics industry is rapidly developed, and is highly valued by the state and market. As an important component of power electronics, capacitors are particularly important for reliability and safety of their operation. The air conditioner controller precharge circuit detection circuit is shown in fig. 1, and includes a detected portion and a detection circuit portion, wherein the detected portion is a bus capacitor C1, C2, CN. The detection circuit comprises a relay K1, and the relay K1 is used for controlling the on-off of a current loop; the relay driving circuits R2, R3 and T1 have the function of ensuring that the relay obtains enough driving voltage; the voltage follower A1 is used for collecting the voltage on the charging resistor R1; a voltage comparator A2 for comparing the voltage of the charging resistor R1 with a set value VCC3 and outputting a comparison result; the main chip MCU is used for providing a control signal and recording the charging time of each time; a charging resistor R1, which functions to constitute a charging loop, and can set a charging end time by setting a resistance value of R1; the bus charging voltage VCC1, which functions to provide a charging power supply for the circuit.
The detection circuit of the precharge circuit of the electric automobile can be divided into the following two working conditions:
(1) The capacitor has no aging fault, and the capacitance value of the capacitor is not reduced.
At this moment, the detection circuit starts to work, the control chip MCU sends a high level signal H1 and starts timing, the relay driving circuit drives the relay K1 to be closed after receiving the signal, a circuit forms a path, the first bus charging voltage VCC1 charges the capacitor C through the charging resistor R1, the capacitor voltage is continuously increased in the charging process, the charging resistor R1 voltage is continuously reduced, when the voltage on the charging resistor R1 is smaller than the set value VCC3, the L1 is changed from high level to low level, and the control chip MCU stops timing and calculates the charging time T3 after receiving the signal. T3 and the initial charge time T3 1 In comparison, at this time, since the capacitor has no aging failure, the capacitance of the capacitor is not reduced, and the charging time T3 and the initial charging time T3 1 The difference DeltaT after comparison 3 Less than delta T, and not reaching alarm limit, MCU does not send alarm signal.
(2) The capacitor suffers from aging failure, and the capacitance of the capacitor is reduced.
At this moment, the detection circuit starts to work, the control chip MCU sends a high-level signal H1 and starts timing, the relay driving circuit drives the relay K1 to be closed after receiving the signal, a circuit forms a path, the first bus charging voltage VCC1 charges the capacitor C through the charging resistor R1, the capacitor voltage is continuously increased in the charging process, the charging resistor R1 voltage is continuously reduced, and when the voltage on the charging resistor R1 is smaller than the set value VCC3, the L1 is formed by the high levelWhen the voltage is changed to the low level, the control chip stops timing and calculates the charging time T3 after receiving the signal. T3 and the initial charge time T3 1 In comparison, at this time, due to the aging failure of the capacitor, the capacitance of the capacitor is reduced, and the charging time T3 and the primary charging time T3 are reduced 1 The difference DeltaT after comparison 3 And when the alarm signal is larger than delta T and reaches the alarm limit value, the MCU sends the alarm signal. And prohibiting the normal start-up operation of the system. The capacitor needs to be replaced.
The main functions of the invention are as follows: the method is applied to the aging detection circuits and the aging detection methods of various air-conditioning capacitors.
In view of the above, after reading the present document, those skilled in the art should make various other corresponding changes without creative mental effort according to the technical scheme and the technical conception of the present invention, which are all within the scope of the present invention.

Claims (8)

1. A detection method for an air conditioner precharge circuit detection circuit, the detection circuit comprising:
the detected part: a bus capacitor circuit;
the detection part: the relay circuit, the voltage circuit and the main controller;
the input end of the main controller is connected with the relay circuit, the relay circuit is connected with the bus capacitor circuit, the bus capacitor circuit is connected with the voltage circuit, and the output end of the voltage circuit is connected with the main controller;
comprising a charging resistor voltage V R1 The method comprises the following steps:
the control chip sends out a high-level signal H1 and starts timing;
the relay receives a high-level signal H1 to drive the relay to be closed, and the charging voltage of the first bus starts to charge the capacitor through the charging resistor;
judging the voltage V of the charging resistor R1 Whether less than the steady state voltage division across the charging resistor R1;
if yes, the control chip receives the low level signal, stops timing and calculates the time difference, and marks as DeltaT 3 ,△T 3 The method comprises the steps that the difference value between a timing value after a control chip receives a low-level signal and a timing value after a previous control chip receives the low-level signal is obtained;
if not, the capacitor continues to charge.
2. The method for detecting an air conditioner precharge circuit according to claim 1, wherein the relay circuit comprises a relay driving circuit, a relay, and a relay voltage; one end of the relay driving circuit is connected with the main controller, the other end of the relay driving circuit is connected with the relay, and the other end of the relay is respectively connected with the relay voltage and the bus capacitor circuit.
3. The method according to claim 2, wherein the relay driving circuit includes a second resistor, a third resistor and a triode, the second resistor is connected to the third resistor and the triode, the other end of the third resistor is connected to the triode, the triode is connected to the relay, and the second resistor is connected to the main controller.
4. The detection method for an air conditioner pre-charge loop detection circuit of claim 1, wherein the voltage circuit comprises a voltage comparator, a voltage follower, a second bus charging voltage, and a third bus charging voltage; one end of the voltage comparator is connected with the main controller, and the other end of the voltage comparator is respectively connected with the voltage follower, the second bus charging voltage and the third bus charging voltage; and the other end of the voltage follower is respectively connected with the second bus charging voltage and the bus capacitor circuit.
5. The detection method for an air conditioner pre-charge loop detection circuit of claim 1, wherein the bus capacitor circuit comprises a bus capacitor, a first bus charging voltage, and a charging resistor; one end of the bus capacitor is connected with the relay circuit, the other end of the bus capacitor is connected with the first bus charging voltage, the other end of the first bus charging voltage is connected with the charging resistor, and the charging resistor is connected with the voltage circuit.
6. The detection method for the air conditioner pre-charge circuit detection circuit according to claim 1, wherein the main controller is a main control chip MCU.
7. The detecting method for an air conditioner pre-charge circuit detecting circuit according to claim 1, further comprising a capacitor aging judging method after stopping the timer and calculating the time difference, comprising the steps of:
determining a time difference DeltaT 3 Whether the time difference set value delta T is larger than the time difference set value delta T;
if yes, judging that the capacitor is aged, and sending an alarm signal by the main controller;
if not, judging that the capacitor is not aged, and the circuit works normally.
8. An air conditioner comprising a detection method for an air conditioner precharge circuit detection circuit as claimed in any one of claims 1 to 7.
CN202111510362.1A 2021-12-10 2021-12-10 Detection method for air conditioner precharge circuit detection circuit and air conditioner Active CN114280377B (en)

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